(1) Field of the Invention
The present invention relates to a method for joining and separating an adhesive tape such as a protective tape to and from a pattern formation side of a semiconductor wafer.
(2) Description of the Related Art
A chip component is fabricated from a semiconductor wafer (hereinafter, appropriately referred to as a “wafer”) in the following manner. For example, a circuit pattern is formed on a front face of a wafer, and then a protective tape is joined to the front face of the wafer. Thereafter, a back face of the wafer is subjected to a grinding process (back grinding) such that the wafer has a small thickness. The wafer having the small thickness is attached to and held by a ring frame through a dicing tape. Thereafter, the protective tape is separated from the front face of the wafer, and then the wafer is transported to a dicing process (refer to, for example, JP-A 2002-124494).
As described above, the processing for the semiconductor wafer involves joining or separating various adhesive tape, such as joining the protective tape to the semiconductor wafer, joining the semiconductor wafer to the dicing tape and separating the protective tape from the semiconductor wafer.
In a case where the semiconductor wafer is subjected to the processing of joining or separating such an adhesive tape, however, since a strength of the semiconductor wafer is insufficient due to its small thickness, there is a high risk of a damage of the semiconductor wafer due to a stress applied to the wafer when the adhesive tape is joined to/separated from the wafer. In particular, a minute chip or crack occurs at an outer periphery of the wafer in the back grinding. In such a case, there is a high possibility that the chip or the crack becomes deteriorated due to the stress applied to the wafer when the adhesive tape is joined to/separated from the wafer.